The present invention relates to power transmission mechanisms and relates more particularly to a power transmission mechanism for a motorized hand tool which has a clutch means which automatically disconnects the tool from the driving shaft thereof when the tool bears a resisting force which surpasses the driving force from the driving shaft.
In regular motorized hand tools, a tool (which may be a bit, drill or blade) is generally attached to a power transmission mechanism and driven to rotate on a workpiece for processing. The power transmission mechanism is continuously transmitting kinetic energy from a driving motor to the bit causing it to rotate. Because there is no clutch means set in the power transmission mechanism, the tool may be damaged easily when it bears a resisting force from a workpiece which surpasses the driving force from the transmission mechanism.